Perastaltic pump

ABSTRACT

A perastaltic pump having a plurality of rollers mounted on a rotating pump wheel. Compressible tubing is supported by a tube support means which is manually operable to move the tubing into engagement with the rollers on the pumping wheel. Through the novel shape of the tubing support means, the tube may be easily installed and removed and functions to prevent tubing creep during operation.

United States Patent H 1 3,597,124

[72] Inventor Robert P. Adams 328,472 10/1885 Faller 103/149 h -Y-2,102,523 12/1937 Ferrara et al.- 103/149 [21] Appl. No. 855,2142,899,906 8/1959 Becher et a1 103/149 [22] Filed Sept. 4,1969 3,421,447l/l969 Jackson et a1. 103/149 [45] Patented Aug. 3, 1971 Assignee CencoMIi I" H pp y Corporation Primary Examiner-Carlton R. Croyle AssistantExaminer-Wilbur J. Goodlin Chicago Attomey-Robert E. Wagner [54]PERASTALTIC PUMP 2 Claims, 7 Drawing Figs.

(52] U.S.C| 417/477 1 Fo4b 43/12 ABSTRACT: A perastaltic pump having aplurality of rollers [50] Field of Search 103/149; mounted on a rotatingpump whee] Compressible tubing is 230/168; 91/57; 7/477, supported by atube support means which is manually operable to move the tubing intoengagement with the rollers on the [56] References CM pumping wheel.Throughthe novel shape of the tubing sup- UNITED STATES PATENTS portmeans, the tube may be easily installed and removed and 271,257 1/1883Morton 103/ l 49 functions to prevent tubing creep during operation.

Patented Aug. 3, 1971 2 Sheets-Sheet 1 INVENTO/r" ROBERT P ADAMS BY I/Q] mm) GM 6 gy ATTY Patented Aug. 3, 1971 2 Sheets-Sheet 2 INVENTORROBERT I? ADAMS BY MflWATT I X PERASTALTIC PUMP This invention relatesto positive-type displacement pumps in general and, more specifically,is directed to a new and imroved perastaltic pump of the type commonlyused in biological, medicinal, chemical, industrial, surgical,pathological and similar type uses.

Perastaltic pumps, as such, are well known in the art and have filled adefinite need in the industry over the years where it is desirable toisolate and control the flow through flexible tubing. Since the tubingforms the path for the fluid pumped and is readily removed, it may beautoclaved as a unit or fresh sterilized tubing substituted whenrequired for diverse uses or experiments.

One problem which has existed in the prior art is the difficultyencountered in installation and removal of the tubing in prior artdesigns. No doubt, this difficulty was a result of proposed solutions tothe problem of preventing tubing creep during the pumping cycle. Variousmeans have been proposed to eliminate these problems, however, prior tothe present invention, no solution has been proposed which would offer asimple and satisfactory answer.

The present invention provides a new and improved tubemountingarrangement in a perastaltic pump which permits the tubing to be easilyinstalled and removed while preventing tubing creep without the use ofcomplicated clamps or the like. A relatively simple cam-biased tubesupport is mounted for angular movement to disengage the tubing from therollers carried on the pump wheel and permits lateral removal andinstallation. The cam permits the pressure on the tubing to be adjustedto the requirements of the tubing used.

It is an object of this invention to provide a new and improvedperastaltic pump.

It is a further object of this invention to provide a new and improvedtube-mounting arrangement for a perastaltic pump which permits removaland installation of the tubing with unequalled ease.

It is a still further object of this invention to provide a new andimproved perastaltic pump having a simplified cam-biased tubing supportmeans which prevents tubing creep during the pumping operation.

Objects in addition to those heretofore stated will appear from thefollowing description made in reference to the accompanying drawingswherein:

FIG. 1 is a front elevational view of the perastaltic pump of thepresent invention with the tubing in position for pumping;

FIG. 2 is a view similar to FIG. 1 with the tubing removed;

FIG. 3 is an enlarged fragmentary elevational view with the pumpingwheel broken away to show the cooperation of the rollers with the tubingand tubing support means;

FIG. 4 is a fragmentary side elevational view taken generally along theline 4-4 of FIG. 1;

FIG. 5 is a fragmentary side elevational view taken generally along theline 5-5 of FIG. 1;

FIG. 6 is a free body front elevational view of the tubing supportmeans; and

FIG. 7 is a cross-sectional view taken generally along the line 7-7ofFIG. 6.

Referring now to FIG. 1, reference numeral 10 indicates the perastalticpump of the present invention including a pump housing 11 and frontcover 12 which mounts a tubing support means indicated generally at 13and a pumping wheel indicated generally at 14. The cover 12 also forms amounting area for a switch 17 for turning the pump on and off and whichmay also have an indicator light 18 included in the circuit for visuallydetecting the condition of the pump.

A tube is wrapped around the tubing support means 13 in a manner to bedescribed in greater detail in connection with FIGS. 3 and 6. A manuallyoperated cam means 16 is mounted at the lower end of the housing 12 andcooperates with the tubing support means in a manner to become apparent.

Referring now to FIGS. 3--5, it can be seen that the pump wheel 14includes spaced-apart plates 20 and 21 held on a shaft 19 and mounting aplurality of rollers 23 for rotation about individual shafts 24. As thepumping wheel 14 rotates, the rollers 23 are brought into engagementwith the tubing 15, compressing it in a manner similar to that shown inFIGS. 1 and 3 and forcing the liquid through the tube 15. This functionwill be described in greater detail when the operation of the pump isgiven.

Referring now to FIG. 6, it can be seen that the tube support means 13includes a tube-mounting portion 30 which may be formed with a shallowgroove 31 which may be generally arcuate in cross section, conforminggenerally to the shape of the tubing to be supported. When viewed alongits length, the groove 31 extends at an angle 32 to a point where thetubesupporting surface is generally tangential to, however, spaced fromthe path generated by pumping wheel 14. The tangential portion 33 mergeswith a smooth arcuate tube-reversing portion 34 which changes thedirection of the tube support slightly in excess of The tubing 15 thenenters the arcuate portion 34 formed on a radius of curvaturesubstantially congruent. to the path traced by the rollers 23 at theirouter extremity. The arcuate portion 34 terminates smoothly, merginginto a straight or linear section 35 for leading the tube 15 away fromthe pumping area to the discharge area where the flow is directed.Retaining lugs 36 and 37 cooperate with the straight or linear mountingsections 33 and 35, respectively, to maintain the tube 15 positioned inthe groove 31 on the tubemounting means.

As shown in FIGS. 3 and 7, an elastomeric pad 38 may line at least apart of the arcuate groove 34 to back the tube 15 in the area where therollers 23 are actively squeezing the tube to perform the pumpingfunction. The tube support means 13 is mounted for pivoting movement onthe face 12 of the pump housing 11 through a bearing bolt 40 or theequivalent.

As best seen in FIGS. 1-3, the cam means 16 consists of a knoblikemember 41 mounted through a pivot pin 44 and having a handle 42 whichextends well outwardly of the housing cover 12 for ease of operation bythe lab assistant or technician. The knob 41 is provided with a slowrise cam surface 43 and fiat side 46. As the handle 42 is manuallyrotated, the cam surface 43 engages a cooperating or follower surface 45on the tube support means 13 to move the tube support means about thepivot 40 and bring the tube 15 into engagement with the rollers 23. Asshown in FIG. 2, when the cam is rotated to a position where the fiatside 46 opposes the cam follower 45, the tube support means moves to thecondition shown to facilitate easy removal and installation of the tube.

Operation of the perastaltic pump of the present invention is easilyaccomplished. A tube partially filled with a liquid is placed on thetube support means 13. The cam means 16 is rotated to bring the tubesupport and installed tubing 15 into engagement with the rollers 23 asshown in FIGS. 1 and 35. The pumping wheel 14 may then be turned on viaswitch 17 for rotation or, if desired, the pumping wheel 14 can bestarted in advance of moving the tubing into engagement with the rollers23. Pumping of the liquid will continue so long as a fluid supply isavailable at the intake.

If desired, the pumping rollers 23 may be increased in overall lengthand multiple tracks provided on a single tubing support means of thesame shape as that shown with the grooves supporting the tubing beingparallel to each other. In this manner, uniform engagement of the tubingand rollers is assured for uniform pumping. This is especially helpfulin those situations where the liquid is to be withdrawn while another isto be added at an equal rate. Through the use of a tubing support meansof the type described herein, the tubing may be readily installed andremoved, eliminating the need for special clamps and the like. Tubingcreep is positively prevented without any need to constrict the tubing.Lateral stability is provided by the elastomeric pad 38 in the pumpingregion. The simplified design provides for a relatively inexpensive pumpwhich is capable of extremely high performance characteristics. In thepresent design, a motor available on the open market having a mechanicalbrake is used to permit microvolumes to be pumped at desired intervalswhen coupled to a suitable timer.

Upon a consideration of the foregoing, it will become obvious to thoseskilled in the art that various modifications may be made withoutdeparting from the invention embodied herein.

1 claim:

1. In a perastaltic-type pump having a pump housing supporting a pumpingwheel, said pumping wheel having means for engagement with a flexibletube through which material is pumped, the improvement comprising a tubesupport means mounted on said housing for movement toward and away fromsaid pumping wheel, a tubing support surface on said tube support means,said tubing support surface being of generally U- shaped configurationto reverse the direction of the tube thereon and thereby prevent tubingcreep during operation of said pump, said tube support surface includingan angular entrance portion merging into a substantially linear sectionradially spaced from said pumping wheel, said linear section mergingwith a generally U-shaped end portion leading into a smooth arcuateportion adapted to be moved to a position closely spaced from saidpumping wheel and a generally linear portion exiting from said arcuateportion.

2. The improvement is perastaltic-type pumps as defined in claim 1wherein lug means is provided an opposition to each of said linearsections, said lug means maintaining said tube in contact with saidlinear sections to prevent tube creep during operation of said pump.

1. In a perastaltic-type pump having a pump housing supporting a pumpingwheel, said pumping wheel having means for engagement with a flexibletube through which material is pumped, the improvement comprising a tubesupport means mounted on said housing for movement toward and away fromsaid pumping wheel, a tubing support surface on said tube support means,said tubing support surface being of generally U-shaped configuration toreverse the direction of the tube thereon and thereby prevent tubingcreep during operation of said pump, said tube support surface includingan angular entrance portion merging into a substantially linear sectionradially spaced from said pumping wheel, said linear section mergingwith a generally U-shaped end portion leading into a smooth arcuateportion adapted to be moved to a position closely spaced from saidpumping wheel and a generally linear portion exiting from said arcuateportion.
 2. The improvement is perastaltic-type pumps as defined inclaim 1 wherein lug means is provided an opposition to each of saidlinear sections, said lug means maintaining said tube in contact withsaid linear sections to prevent tube creep during operation of saidpump.